Development Review of the BACE1 Inhibitor Lanabecestat (AZD3293/LY3314814)

Efficacy and Safety of Lanabecestat for Treatment of Early and Mild Alzheimer Disease: The AMARANTH and DAYBREAK-ALZ Randomized Clinical Trials

Importance

Alzheimer disease (AD) is a neurodegenerative disorder characterized by cognitive deterioration and impaired activities of daily living. Current treatments provide only minor symptomatic improvements with limited benefit duration. Lanabecestat, a brain-permeable inhibitor of human beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1/β-secretase), was developed to modify the clinical course of AD by slowing disease progression.

Objective

To assess whether lanabecestat slows the progression of AD compared with placebo in patients with early AD (mild cognitive impairment) and mild AD dementia.

Design, Setting, and Participants

AMARANTH (first patient visit on September 30, 2014; last patient visit on October 4, 2018) and DAYBREAK-ALZ (first patient visit on July 1, 2016; last patient visit on September 28, 2018) were randomized, placebo-controlled, phase 2/3 and phase 3 clinical trials lasting 104 weeks and 78 weeks, respectively. AMARANTH and DAYBREAK-ALZ were multicenter, global, double-blind studies conducted at 257 and 251 centers, respectively, located in 15 and 18 countries or territories, respectively. A population-based sample of men and women aged 55 to 85 years who met National Institute on Aging-Alzheimer's Association criteria for early AD or mild AD dementia was screened using cognitive assessments, and the presence of amyloid was confirmed. Patients were excluded for unstable medical conditions or medication use, significant cerebrovascular pathologic findings, or a history of vitiligo and/or current evidence of postinflammatory hypopigmentation. AMARANTH screened 6871 patients; 2218 (32.3%) were randomized, and 539 patients completed the study. DAYBREAK-ALZ screened 5706 patients; 1722 (30.2%) were randomized, and 76 patients completed the study.

Interventions

Patients were randomized (1:1:1) to once-daily oral doses of lanabecestat (20 mg), lanabecestat (50 mg), or placebo.

Main Outcomes and Measures

The primary outcome measure was change from baseline on the 13-item Alzheimer Disease Assessment Scale-cognitive subscale. Secondary outcomes included Alzheimer's Disease Cooperative Study-Instrumental Activities of Daily Living Inventory, Clinical Dementia Rating, Functional Activities Questionnaire, Mini-Mental State Examination, and Neuropsychiatric Inventory. Efficacy analyses were conducted on the intent-to-treat population.

Results

Among 2218 AMARANTH patients, the mean (SD) age was 71.3 (7.1) years, and 1177 of 2218 (53.1%) were women. Among 1722 DAYBREAK-ALZ patients, the mean (SD) age was 72.3 (7.0) years, and 1023 of 1722 (59.4%) were women. Both studies were terminated early after futility analysis. There were no consistent, reproducible dose-related findings on primary or secondary efficacy measures. Psychiatric adverse events, weight loss, and hair color changes were reported in a higher percentage of patients receiving lanabecestat than placebo.

Conclusions and Relevance

Treatment with lanabecestat was well tolerated and did not slow cognitive or functional decline.

Trial Registration

ClinicalTrials.gov identifiers: NCT02245737 and NCT02783573.

Targeting Amyloidogenic Processing of APP in Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of senile dementia, characterized by neurofibrillary tangle and amyloid plaque in brain pathology. Major efforts in AD drug were devoted to the interference with the production and accumulation of amyloid-β peptide (Aβ), which plays a causal role in the pathogenesis of AD. Aβ is generated from amyloid precursor protein (APP), by consecutive cleavage by β-secretase and γ-secretase. Therefore, β-secretase and γ-secretase inhibition have been the focus for AD drug discovery efforts for amyloid reduction. Here, we review β-secretase inhibitors and γ-secretase inhibitors/modulators, and their efficacies in clinical trials. In addition, we discussed the novel concept of specifically targeting the γ-secretase substrate APP. Targeting amyloidogenic processing of APP is still a fundamentally sound strategy to develop disease-modifying AD therapies and recent advance in γ-secretase/APP complex structure provides new opportunities in designing selective inhibitors/modulators for AD.

Clinically Negligible Pharmacokinetic and Pharmacodynamic Interactions Between Lanabecestat and Dabigatran Etexilate, a Prototypical P-gp Substrate

Lanabecestat, a novel β-site amyloid precursor protein-cleaving enzyme 1 inhibitor evaluated for Alzheimer treatment, inhibits P-glycoprotein (P-gp) activity in vitro. After oral 50-mg lanabecestat administration, gastric fluid lanabecestat concentrations exceed half-maximal inhibitory concentration (IC₅₀ ), suggesting P-gp inhibition at the intestinal wall. Plasma drug concentrations following 50 mg lanabecestat administered once daily are <10% of IC₅₀ , suggesting minimal systemic P-gp interaction. Dabigatran etexilate (DE) is the prodrug of dabigatran, a thrombin inhibitor and P-gp substrate, making dabigatran exposure an intestinal P-gp activity indicator. This study (NCT02568397) was conducted in 60 healthy subjects receiving a single dose of 150 mg DE alone or during a lanabecestat treatment regimen. On day 16, lanabecestat and DE were coadministered; on day 20, DE was dosed 4 hours after lanabecestat. Safety was assessed using clinical labs, electrocardiogram, vital signs, Columbia Suicide Severity Rating Scale scores, adverse events, and eye and skin examinations. Pharmacokinetic/pharmacodynamic samples were collected up to 36 hours postdose. Geometric mean plasma dabigatran area under the curve from time 0 to infinity (AUC_0-∞ ) and the maximum plasma drug concentration (C_max ) increased by 15% and 17%, respectively, when coadministered with lanabecestat. When DE was dosed 4 hours after lanabecestat, there was no effect on plasma dabigatran AUC_0-∞ , C_max , or thrombin time. DE had no effect on lanabecestat's AUC_0-∞ and C_max at steady state (day 16) versus lanabecestat alone (day 15). No clinically relevant safety concerns were observed. Lanabecestat has no clinically meaningful effect on dabigatran exposure or on P-gp activity at the intestinal wall.

[Innovation in diagnostics-mobile technologies]

BACKGROUND

Progressive cognitive deficits are the main clinical symptom of Alzheimer's disease; however, the precise recording of cognitive deficits and assessment of their progression pose major problems in patient care and early interventions.

OBJECTIVE

Which problems for care and early intervention result from the current practice of cognitive assessment of patients with memory problems and which opportunities arise from the use of mobile apps?

MATERIAL AND METHODS

Evaluation of current care structures, discussion of basic work, expert recommendations and current developments.

RESULTS

The current practice of the pencil and paper-based diagnostics of cognitive deficits, which is temporally and spatially bound to a clinical environment, constrains the feasibility, validity and reliability of cognitive assessment and the quantification of progression. This limits the meaningful use of further diagnostic measures, such as magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analyses. Recent progress in mobile app-based technologies, illustrated here with the example of the neotiv app, can help to overcome these problems.

CONCLUSION

Mobile app-based technologies can help to improve the cognitive assessment of patients with the main symptom of memory complaints. They can reduce overuse and underuse of diagnostic and therapeutic pathways and enable a targeted and meaningful use of advanced diagnostics. In addition, they can structure risk-modifying preventive measures, identify iatrogenic impairment of cognition and in this respect also strengthen patient competence.

A Close Look at BACE1 Inhibitors for Alzheimer's Disease Treatment

Alzheimer's disease (AD), the most common cause of age-dependent dementia, is one of the most significant healthcare problems worldwide. Aggravating this situation, drugs that are currently US Food and Drug Administration (FDA)-approved for AD treatment do not prevent or delay disease progression. Therefore, developing effective therapies for AD patients is of critical urgency. Human genetic and clinical studies over the past three decades have indicated that abnormal generation or accumulation of amyloid-β (Aβ) peptides is a likely culprit in AD pathogenesis. Aβ is generated from amyloid precursor protein (APP) via proteolytic cleavage by β-site APP cleaving enzyme 1 (BACE1) (memapsin 2, β-secretase, Asp 2 protease) and γ-secretase. Mice deficient in BACE1 show abrogated production of Aβ. Therefore, pharmacological inhibition of BACE1 is being intensively pursued as a therapeutic approach to treat AD patients. Recent setbacks in clinical trials with BACE1 inhibitors have highlighted the critical importance of understanding how to properly inhibit BACE1 to treat AD patients. This review summarizes the recent studies on the role of BACE1 in synaptic functions as well as our views on BACE1 inhibition as an effective AD treatment.

Systems Pharmacological Approach to Investigate the Mechanism of Acori Tatarinowii Rhizoma for Alzheimer's Disease

In traditional Chinese medicine (TCM), Acori Tatarinowii Rhizoma (ATR) is widely used to treat memory and cognition dysfunction. This study aimed to confirm evidence regarding the potential therapeutic effect of ATR on Alzheimer's disease (AD) using a system network level based in silico approach. Study results showed that the compounds in ATR are highly connected to AD-related signaling pathways, biological processes, and organs. These findings were confirmed by compound-target network, target-organ location network, gene ontology analysis, and KEGG pathway enrichment analysis. Most compounds in ATR have been reported to have antifibrillar amyloid plaques, anti-tau phosphorylation, and anti-inflammatory effects. Our results indicated that compounds in ATR interact with multiple targets in a synergetic way. Furthermore, the mRNA expressions of genes targeted by ATR are elevated significantly in heart, brain, and liver. Our results suggest that the anti-inflammatory and immune system enhancing effects of ATR might contribute to its major therapeutic effects on Alzheimer's disease.